This invention relates to multi-hulled boat configurations and outrigger type float mounting construction. In particular, it relates to catamaran-type twin-hulled boats with articulated hull suspension enabling the overall beam width of the boat to be narrowed when desired to substantially a single hull configuration.
Ocean-cruising catamarans have been known for over 3,000 years. Heretofore, such multi-hulled boats have often been difficult and awkward to maneuver in relatively tight marina berthing procedures, or in packed anchorage areas. This is primarily due to their comparatively massive beam width. Additionally, these wonderfully performing open-water craft are non transportable by motor-trailer because of their girth. Efforts have been made by inventors to overcome this particular difficulty by collapsing the hulls in various ways, generally resulting in serious design compromises. The previous improvements have been less than satisfactory.
There are two basic practical approaches to variable-beam-width catamarans. One is using telescoping transverse-tubes that slide the hulls together. The other is using pivoting swingarms that narrowingly tilts or swings the hulls inward. Otherwise, the procedure is to spend hours in dismantling or collapsing the entire vessel.
The early prior art is illustrated by U.S. Pat. No. 2,678,018, which shows a boat having dual, lateral (right and left) 3-position, stabilizing hulls. These hulls were articulated by a first set of horizontally spaced parallel arms set on a longitudinally arranged pivot-axis, which served to fold the hulls 90 degrees beneath the main center hull. In this movement, the stabilizing hulls are rotated so that the outer side contacts the surface of the water. A second set of pivot arms act on axes arranged vertically to the horizontal first set of arms, to further outset the float members on a horizontal plane of swing action. This system suffers from loss of hull configuration when the outrigger hulls are folded under the center hull, making the hulls essentially useless other than for flotation, and would tend to take on water in the rotated attitude unless fully sealed. So this configuration is inappropriate to adapt as a sea-going, cabin-hulled, the catamaran-craft configuration.
The U.S. Pat. No. 2,917,754 shows a simple light-weight catamaran configuration with laterally opposed hulls pivotally mounted to a horizontal center panel as to enable them to neatly fold above the center panel, one hull into the other. This allows the folded assembly to be readily mounted atop a car roof, for example. However, this is a simple small craft that is not adaptable to be used in a cabin-hull configuration.
U.S. Pat. No. 3,593,684 discloses a collapsible multi-purpose catamaran-type craft in which two laterally opposed hulls are slideably joined to dual transverse tubular members held by a third center section frame. Owing to the considerable physical weight involved in a larger sea-going craft, the system is only practical for small light-weight boats.
The disclosure of U.S. Pat. No. 3,937,166 shows a trimaran sailcraft having a folding-hull member pivoting upon longitudinal axes at each outermost right and left sides of the cabin structure. This is achieved without disturbing the center cabin occupancy. In this method, the hulls are cantilevered transversely out on pivot arms. However, the outboard hulls are useless for cabin occupancy or buoyancy, since they rotate about 80 degrees upon their sides when deployed into their fully retracted position. Hence, this configuration lacks the spatial volumetric efficiency which the present invention teaches elsewhere herein, whereby outrigger hulls can also provide comfortable occupancy; efficiently utilizing the otherwise dead-weight, draft drag imposed by the stabilizer hulls of this old art.
The invention of U.S. Pat. No. 3,981,259 shows a small fishing catamaran having dual, extensible hulls, which pivot 90 degrees laterally on spaced longitudinal axes so as to be swung inward beneath the planar mid-frame (supporting a cabin) or outward from the mid-frame, as controlled by telescopic rams. Because of the swinging arrangement, the hull design is only vertical to the water at mid-position; and thus would not provide suitable cabin occupancy because only the center platform remains horizontal to the water. A so-called collapsible catamaran is shown in U.S. Pat. No. 3,986,219, which is a small light-weight embodiment having a horizontal rectangular tube framework with quick disconnects which enable the boat to be taken apart in sections and packed in one compact package if desired. But there is no provision for varying the beam width. While U.S. Pat. No. 4,286,533 shows a catamaran featuring a transversely fixed overall hull beam, the center flying platform is able to be moved laterally thereto, enabling a sailor to bias the deck to one side or the other so as to weightably counteract the force of the wind.
A tri-hulled sailing craft is shown in U.S. Pat. No. 4,294,184 which exhibits variable hull beam width capability by means of laterally spaced, pivot arms acting on longitudinal axes. Yet here again the hulls become undesirably inverted some 180 degrees when swung through their full swing limit, making the hulls unusable for cabin occupancy. A rather barge-like trimaran boat is shown in U.S. Pat. No. 4,337,543, wherein a solid planar deck is exhibited having two longitudinal pivot axes at the deck enabling the laterally spaced outer quarter sections of the hull to be manually pivoted 90 degrees beneath the hull center section, thereby achieving more compact storage.
In U.S. Pat. No. 4,441,445 the trimaran sailboat has laterally well spaced, articulated outrigger hulls powered by telescopic rams, the purpose being to enable the boat to right itself if it should become inverted while sailing in high wind conditions. Again, the arrangement uses opposed right and left transverse arms having longitudinal pivots, but the axes are set well outboard of the center hull so that the floats carried distally on the arms may be moved by telescopic rams some 220 degrees in order to perform a self righting action.
In U.S. Pat. No. 4,730,570, a variable beam trimaran is set forth employing outrigger floats which are connected to the center hull by means of several discrete transverse support tubes. This sliding tube arrangement facilitates narrowing of the overall beam width, yet seriously interferes with cabin occupancy space in the center main hull.
More recently, U.S. Pat. No. 4,766,830 discloses a simple lightweight catamaran that readily disassembles rather than function as a variable beam. Another U.S. Pat. No. 4,807,551, shows an ordinary canoe boat, adapted with a simple arrangement of dual transverse tubes secured to the hull at both sides, and a pontoon float set distally outboard therefrom. Finally, U.S. Pat. No. 4,977,844 shows a simple rowboat adapted with a single lateral arm member having a narrow curved float that retracts closely against the side of the likewise curved hull side.
It is clear from the prior art and a survey of the marketplace that there are presently no catamaran vessels of practical sea-going configuration capable of meeting the popular needs of the sailing public, either as to a practical, readily variable hull beam width, or one which when retracted still maintains a constant vertical attitude to the cabin area within the laterally opposed hulls. Therefore, the present invention herein disclosed a high performance catamaran both in sailboat and powerboat embodiments.